Why Airplane Windows Are Round, Explained in 2 Minutes

Ever gazed out at your plane taking off and wondered why your plane windows always have rounded edges, unlike the hard corner in your home? There's a simple and very good reason, as explained by this clever little video.

As commercial air travel took off in the mid-20th century, airline companies began to fly at higher altitudes to save money—the air density is lower up there, creating less drag for airplanes. But for passengers to survive at 30,000 feet, the cabin must be pressurized.

To make that possible, the cabin was changed to a cylindrical shape to support the internal pressure. But at first, plane builders left in the standard square windows. Bad move: As the video demonstrates, pressure builds more around the corners of square windows. Three airplanes with square windows crashed in the 1950s after the fuselages tore apart during flight.

Fortunately, designers figured out the design flaw pretty quick. Now we have nice, round windows that can withstand the pressure of cruising altitude.